Lamination Device and Method for Discharging Defective Electrode Cell Assembly of Lamination Device

ABSTRACT

A lamination apparatus configured to manufacture an electrode cell assembly may include a lamination part configured to manufacture the electrode cell assembly through lamination, an inspection part configured to detect a defective electrode cell assembly by measuring a thickness of the manufactured electrode cell assembly, a discharge part configured to separate and discharge the defective electrode cell assembly from a normal electrode cell assembly, and a control part configured to perform control so as to calculate a time point at which the defective electrode cell assembly reaches the discharge part on the basis of distance data between a point at which the defective electrode cell assembly is detected and the discharge part and separate and discharge the defective electrode cell assembly when the defective electrode cell assembly reaches the discharge part. A method of discharging a defective electrode cell assembly by the lamination apparatus is also disclosed.

TECHNICAL FIELD

The present invention relates to a lamination apparatus configured tomanufacture an electrode cell assembly by laminating an electrode and aseparator, and more particularly, to a lamination apparatus capable ofeffectively separating and discharging a defective electrode cellassembly including a connection tape of an electrode or a separator, anda method of discharging a defective electrode cell assembly by thelamination apparatus.

This application claims the benefit of priority based on Korean PatentApplication No. 10-2021-0016038, filed on Feb. 4, 2021, and the entirecontents of the Korean patent application are incorporated herein byreference.

BACKGROUND ART

As the price for energy sources increases due to the depletion of fossilfuels and interest in environmental pollution is amplified,environmentally friendly alternative energy sources have become anessential factor for future life. In particular, as the technicaldevelopment of and the demand for mobile devices increase, the demandfor secondary batteries as an energy source is rapidly increasing.

In general, secondary batteries refer to batteries that are chargeableand dischargeable unlike primary batteries that are not chargeable, andthe secondary batteries are widely used in various fields such as mobilephones, notebook computers, automobiles, and the like.

Such secondary batteries are manufactured to have a form including anelectrode assembly enclosed in a battery case together with anelectrolyte. In order to manufacture the electrode assembly, alamination process for bonding between an electrode and a separator isrequired.

The lamination process includes unwinding electrodes and separators froman unwinder, cutting the electrodes, conveying the electrodes and theseparators, bonding the electrode and the separator so that theelectrode and the separator are alternately disposed, heating the bondedelectrode and separator, rolling the heated electrode/separator, andcutting the separators after the heating and rolling to manufacture anelectrode cell assembly of a basic unit. At the end of the laminationprocess, a process of inspecting and discharging the bonded andlaminated electrode cell assembly is performed. One or a plurality ofnormal electrode cell assemblies that have passed the inspection may belaminated and received as an electrode assembly in a case to manufacturea secondary battery.

FIG. 1 is a diagram illustrating an example of a conventional laminationapparatus 1000.

As shown, the lamination apparatus 1000 includes a lamination partconfigured to manufacture an electrode cell assembly by laminatingelectrodes 1 and separators 2, an inspection part configured to inspectthe electrode cell assembly, and a discharge part configured todischarge the electrode cell assembly whose inspection is completed.

The lamination part includes unwinder parts 10 and 11, an electrodecutting part 30, electrode/separator conveying parts C1 and C2, abonding part 40, a heating part 50, a rolling part 60, and a separatorcutting part 70. Specifically, the electrodes 1 and the separators 2 areunwound from an electrode unwinder roll 10 and a separator unwinder roll11 of the unwinder parts, respectively, and the electrodes 1 are firstsequentially cut in the electrode cutting part 30. The cut electrode ismoved along first and second conveyors C1 and C2 onto the separator 2,and the electrode 1 and the separator 2 are matched and bonded to eachother in the bonding part 40. Another electrode 1′ (lower electrode) isconveyed to a lower portion of a conveying line for the separator 2 andbonded to the (upper) electrode 1 and the separator 2 in the bondingpart 40. For convenience of illustration, an illustration of a conveyingline for the lower electrode is omitted.

The bonded electrode/separator is heated in the heating part 50 androlled in the rolling part 60, and then the separators 2 are cut in theseparator cutting part 70 to complete an electrode cell assembly E of apredetermined unit. In operations after the heating part 50, theelectrode/separator is conveyed by a third conveyor C3.

The completed electrode cell assembly E is inspected forappearance/dimensions by a camera or the like, and then, conveyed anddischarged to a discharge part 300 to be sent to a subsequent process.

Meanwhile, the electrode 1 and the separator 2 are manufactured in aroll-to-roll manner in electrode and separator manufacturing processesperformed before the lamination process, and in the roll-to-rollmanufacturing process, in order to continuously manufacture theelectrode and separator, a connection portion (splicing portion)connecting a rear end of one roll and a front end of another roll isinevitably included in an electrode roll and a separator roll. Inaddition, when a defect is generated during the manufacturing process,and a connection portion in which the electrode or the separator of thedefected portion is removed and then the rolls are connected again maybe included. The connection portion is formed of a connection tape suchas a polyethylene terephthalate (PET) tape. Since the connection portionis not coated with the electrode or is made of a material different fromthose of an electrode current collector and the separator, when such aportion is included in the electrode cell assembly, a defect occurs.Thus, it is necessary to remove such a defective electrode cell assemblyin the lamination process.

Since the connection tape has a different color from the electrode orthe separator that is a base material, the connection tape may bedetected by a color sensor. That is, as shown in FIG. 1 ,conventionally, color sensors 20 and 20′ have been disposed between theelectrode unwinder roll 10 and the electrode cutting part 30 or near theseparator unwinder roll 11 to detect the connection tape included in theelectrode or the separator. The color sensors 20 and 20′ may eachdistinguish colors by transmitting white light through the electrode orthe separator and then analyzing RGB values of reflected light.

The electrode/separator, which includes the connection tape and isdetected by the color sensors 20 and 20′, is then laminated anddischarged as the electrode cell assembly. In the discharge part 300,among the electrode cell assemblies, the defective electrode cellassembly, in which the connection tape is included in the electrode orthe separator, is adsorbed and removed by a separating and dischargingmember.

When a defective portion, in which the connection tape is included, forexample, in the electrode 1, is detected by the color sensors 20 and20′, a distance A from a defect detection point to the front of theheating part 50 is calculated by encoders (not shown) installed at thefirst and second conveyors C1 and C2, and a distance B until theelectrode cell assembly including a defective electrode reaches thedischarge part is calculated by an encoder (not shown) installed at thethird conveyor C3. Alternatively, when a defective portion is detectedin the separator 2, a distance A from a defect detection point to thefront of the heating part 50 is calculated by an encoder (not shown)installed at the separator unwinder roll 11, and a distance B until theelectrode cell assembly including a defective separator reaches thedischarge part is calculated by an encoder (not shown) installed at thethird conveyor C3. When the distances A and B are calculated, a timepoint at which the defective electrode cell assembly reaches thedischarge part is calculated by dividing the distance by a conveyingspeed of the conveyor or an unwinding speed, and a separate anddischarge member 90 removes the defective electrode cell assembly fromthe conveyor at the time point at which the defective electrode cellassembly reaches (a discharge port of) the discharge part 300. A defectdetection signal is sent to a power line communication (PLC) controlpart (not shown) from the color sensors 20 and 20′, and the PLC controlpart calculates the arrival time point of the defective electrode cellassembly by using predetermined software, and transmits a control signalfor discharging the defective electrode cell assembly to the dischargemember 90 of the discharge part 300.

However, according to the conventional method, the defect detection ispreviously performed in an introduction part of the lamination apparatus1000, and after a long time, the discharge of the defective electrodecell assembly is performed in the discharge part 300, and thus it isdifficult to calculate an accurate discharge time point of the defectiveelectrode cell assembly because a distance between a defect recognitionpoint and the discharge port is too long (approximately 15 to 20 m).That is, since the distance to the discharge part 300 is too long, anerror inevitably occurs in the discharge of the cell assembly specifiedas defective. In addition, an arrival time point of the defectiveelectrode cell assembly is calculated by summing distance valuesrespectively measured by a plurality of encoders because the electrodecell assembly moves, and thus, there is a problem in that a calculationprocess is complicated and time for preserving and processing data isrequired. Furthermore, since the electrode and the separator aresubjected to processes such as cutting, bonding, heating, and rollingafter the unwinder, certain vibrations inevitably occur in the conveyor,and accordingly, a slight change in the conveying speed of the conveyoris generated, and the error at the arrival time point is inevitablylarger.

In the conventional method, the reason in which the color sensors 20 and20′ are installed near the unwinder is that the color sensors 20 and 20′should be installed at a location before the electrodes or separatorsare stacked and cut because the connection tape is not exposed at asurface of the electrode or the separator after the electrode/separatoris bonded and laminated and thus may not be detected by the colorsensors 20 and 20′. Thus, according to the conventional method in whichthe defective electrode cell assembly is detected using the colorsensors 20 and 20′, there is an inevitability that the color sensor fordetecting defects should be installed near the unwinder before theprocess of cutting the electrodes.

According to the conventional connection tape detection method, errorsinevitably occur at an arrival time point of the defective electrodecell assembly at the discharge part. Thus, conventionally, even the cellassemblies before and after the cell assembly, which are presumed toinclude the connection tape, are regarded as defective electrode cellassemblies and discharged. Accordingly, a total of three, in many cases,up to four or five normal cell assemblies, including the cell assemblyactually including the connection tape, are discharged as defectiveelectrode cell assemblies, and thus there is a problem in that productmanufacturing yield is greatly reduced.

Accordingly, it is desired to develop a technique capable of increasingproduct manufacturing yield by accurately discharging only defectiveelectrode cell assemblies in an electrode/separator laminationapparatus.

PRIOR-ART DOCUMENTS Patent Documents

-   Korean Patent Publication No. 10-2167118

DISCLOSURE Technical Problem

An object of the present invention is to provide a lamination apparatuscapable of efficiently discharging only a defective electrode cellassembly including a connection tape by detecting the defectiveelectrode cell assembly among electrode cell assemblies after cuttingelectrodes or separators, and a method of discharging a defectiveelectrode cell assembly by the same.

Another object of the present invention is to provide a laminationapparatus capable of accurately detecting a defective electrode cellassembly by minimizing the effects of bonding, heating, rolling,cutting, and the like an electrode/separator and a method of discharginga defective electrode cell assembly.

Technical Solution

One aspect of the present invention provides a lamination apparatusconfigured to manufacture an electrode cell assembly by laminating anelectrode and a separator respectively unwound from an electrode rolland a separator roll, the lamination apparatus including a laminationpart configured to manufacture the electrode cell assembly throughlamination, an inspection part configured to detect a defectiveelectrode cell assembly by measuring a thickness of the manufacturedelectrode cell assembly, a discharge part configured to separate anddischarge the defective electrode cell assembly from a normal electrodecell assembly, and a control part configured to perform control so as tocalculate a time point at which the defective electrode cell assemblyreaches the discharge part on the basis of distance data between a pointat which the defective electrode cell assembly is detected and thedischarge part and separate and discharge the defective electrode cellassembly when the defective electrode cell assembly reaches thedischarge part.

In an example, the lamination apparatus of the present invention mayobtain the time point at which the defective electrode cell assemblyreaches the discharge part by dividing the distance data by a conveyingspeed of a conveyor.

In a specific example, the distance data may be detected by an encoderinstalled at a conveyor driving part configured to convey the electrodecell assembly.

In another example, the inspection part may include a thicknessmeasuring part for measuring a thickness of the electrode cell assemblyand a vision inspection part configured to inspect at least one of anappearance, a shape, and dimensions of the battery cell assembly.

In a specific example, the thickness measuring part may be installed infront of the vision inspection part.

In an example, the thickness of the battery cell assembly may bemeasured in a non-contact manner.

In a specific example, the thickness of the battery cell assembly may bemeasured by a confocal thickness sensor.

In a preferred example, the confocal thickness sensor may be installedon an XYZ stage.

Further, two confocal thickness sensors may be respectively disposedabove and below the electrode cell assembly, and the thickness of theelectrode cell assembly may be measured by a difference of a distancebetween the electrode cell assembly and the confocal thickness sensordisposed thereabove and a distance between the electrode cell assemblyand the confocal thickness sensor disposed therebelow.

In this case, the two upper and lower confocal thickness sensors may bemounted on one bracket, and the bracket may be installed on an XYZstage.

In another example, in order to ensure the discharge of the defectiveelectrode cell assembly, the control part may perform control such thatone electrode cell assembly adjacent to the defective electrode cellassembly is discharged together with the defective electrode cellassembly.

Another aspect of the present invention provides a method of discharginga defective electrode cell assembly by a lamination apparatus configuredto manufacture an electrode cell assembly by laminating an electrode anda separator, the method including detecting a defective electrode cellassembly by measuring a thickness of the electrode cell assembly afterthe electrode and the separator are laminated to form the electrode cellassembly, calculating a time point at which the defective electrode cellassembly reaches a discharge part on the basis of distance data betweena point at which the defective electrode cell assembly is detected andthe discharge part, and separating and discharging the defectiveelectrode cell assembly from a normal electrode cell assembly at thetime point at which the defective electrode cell assembly reaches thedischarge part.

Advantageous Effects

According to the present invention, a capability of detecting adefective electrode cell assembly is improved as compared with aconventional method of detecting a connection tape at an early stage ofa lamination process. Since a distance for discharging the defectiveelectrode cell assembly after a defect is detected is short, errors inpower line communication (PLC) control can be reduced, such that onlythe defective electrode cell assembly can be discharged relativelyaccurately.

Accordingly, the amount of normal electrode cell assemblies dischargedas defective electrode cell assemblies can be greatly reduced, therebygreatly improving product manufacturing yield.

Further, according to the present invention, a thickness of an electrodecell assembly can be accurately measured despite an impact caused bybonding, heating, rolling, cutting, and the like an electrode/separator,thereby effectively detecting a defective electrode cell assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a conventional laminationapparatus.

FIG. 2 is an overall schematic diagram of a lamination apparatus of thepresent invention.

FIG. 3 is a schematic diagram illustrating details related to themeasurement of a thickness of an electrode cell assembly and the controlof discharging a defective electrode cell assembly by the laminationapparatus of the present invention.

FIG. 4 is a schematic diagram illustrating another embodiment of thelamination apparatus of the present invention.

FIG. 5 is a side view illustrating an actual example of the laminationapparatus to which the present invention is applied.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the detailed configuration of the present invention will bedescribed in detail with reference to the accompanying drawings andvarious embodiments. The embodiments described below are exemplarilyillustrated for understanding of the invention, and the accompanyingdrawings are not shown to actual scale to aid in understanding theinvention, and dimensions of some components may be illustrated as beingexaggerated.

While the present invention is susceptible to various modifications andalternative forms, specific embodiments thereof are shown by way ofexample in the drawings and will be described in detail herein. Itshould be understood, however, that there is no intent to limit thepresent invention to the particular forms disclosed, but on thecontrary, the present invention is to cover all modifications,equivalents, and alternatives falling within the spirit and scope of thepresent invention.

The present invention is related to a lamination apparatus configured tomanufacture an electrode cell assembly by laminating an electrode and aseparator respectively unwound from an electrode roll and a separatorroll, and the lamination apparatus includes a lamination part configuredto manufacture the electrode cell assembly through lamination, aninspection part configured to detect a defective electrode cell assemblyby measuring a thickness of the manufactured electrode cell assembly, adischarge part configured to separate and discharge the defectiveelectrode cell assembly from a normal electrode cell assembly, and acontrol part configured to perform control so as to calculate a timepoint at which the defective electrode cell assembly reaches thedischarge part on the basis of distance data between a point at whichthe defective electrode cell assembly is detected and the discharge partand separate and discharge the defective electrode cell assembly whenthe defective electrode cell assembly reaches the discharge part.

The main feature of the present invention is that the defectiveelectrode cell assembly is detected by measuring the thickness of theelectrode cell assembly excluding the conventional method of using aconnection tape of an electrode or a separator by using a color sensor.Since the conventional method of detecting the connection tape bymeasuring colors of the electrode or the separator may not be appliedafter an electrode/separator is cut and laminated, color sensors 20 and20′ are inevitably disposed before the electrode or the separator is cut(see FIG. 1 ). However, the method of detecting the defective electrodecell assembly, which includes the connection tape, by measuring thethickness of the electrode cell assembly may be applied even after theelectrode/separator is cut and laminated, and thus there is nolimitation as in the conventional method. The connection tape includedin the electrode or the separator has a thickness greater than that ofthe electrode or the separator, which is a base material, and thus theelectrode cell assembly including the connection tape is thicker thanthe normal electrode cell assembly. Thus, when the thickness of theelectrode cell assembly is measured, the defective electrode cellassembly may be detected. For example, there may be anelectrode-separator-electrode laminated cell assembly and anelectrode-separator-electrode-separator-electrode laminated cellassembly, and among them, when the electrode or the separator includedin the cell assembly has a thickness different from a predetermined setthickness, a thickness of the entire cell assembly is also differentfrom a set thickness of the normal cell assembly. The present inventionis completely different from the related art in that the defectiveelectrode cell assembly is detected in a cell assembly state bymeasuring the thickness of the battery cell assembly. As will bedescribed below, the detection of the thickness of the electrode cellassembly may be performed by a confocal thickness sensor.

As described above, in the present invention, since the defectiveelectrode cell assembly is detected by the thickness detection in theelectrode cell assembly stage, a distance between a point at which thedefective electrode cell assembly is recognized (detected) and thedischarge part is very short. In addition, as will be described below,the distance is easily measured by an encoder installed at a conveyorconfigured to convey the electrode cell assembly. Thus, a time point atwhich the defective electrode cell assembly reaches the discharge partmay be easily calculated on the basis of the distance data. Since adistance (2 to 3 m) between the defect detection point and the dischargepart is much shorter than a distance (15 to 20 m) in the conventionalmethod using the color sensor, the calculation of the arrival time pointusing the distance data is very accurate, and an error is not large.Furthermore, in the present invention, since the defective electrodecell assembly is detected at the stage in which the electrode cellassembly is manufactured, the defective electrode cell assembly may bedetected and discharged without being affected by an impact received bythe conveyor caused by electrode cutting, electrode/separator bonding,heating and rolling, separator cutting, and the like. Even when theimpact is applied on the conveyor during a short-distance movementbetween the defect detection point and the discharge part, as will bedescribed below, the defective electrode cell assembly may be accuratelydetected by using the specific confocal thickness sensor of the presentinvention.

The lamination apparatus and a method of discharging a defectiveelectrode cell assembly by the same of the present invention will bedescribed in more detail with reference to the following embodiments andthe accompanying drawings.

Modes of the Invention First Embodiment

FIG. 2 is an overall schematic diagram of a lamination apparatus 2000 ofthe present invention, and FIG. 3 is a schematic diagram illustratingdetails related to the measurement of a thickness of an electrode cellassembly and the control of discharging a defective electrode cellassembly by the lamination apparatus 2000 of the present invention.

In the present embodiment, the same components as those of theconventional lamination apparatus are denoted by the same referencenumerals, and detailed descriptions thereof will be omitted.

As shown in FIGS. 2 and 3 , electrodes 1 and separators 2 arerespectively unwound from an electrode unwinder roll 10 and a separatorunwinder roll 11 in an unwinder part. Thereafter, the electrodes 1 aresequentially cut and conveyed on a first conveyor C1, conveyed to asecond conveyor C2, and placed on the separators 2. In a bonding part40, the electrode 1 is positionally matched and bonded to the separator2. Another electrode 1′ (lower electrode) is conveyed to a lower portionof a conveying line for the separator 2 and bonded to the (upper)electrode 1 and the separator 2 in the bonding part 40. For convenienceof illustration, an illustration of a conveying line of the lowerelectrode 1′ is omitted.

Although the electrode cell assembly in which the electrode, theseparator, and the electrode are laminated is illustrated as an examplein the present embodiment, lamination of an electrode cell assemblyhaving a bi-cell type, for example, anelectrode-separator-electrode-separator-electrode assembly, or otherlaminated structures is also possible. For example, the presentinvention is applicable to any form of a cell assembly as long as it iscapable of measuring a thickness of an assembly and discharging adefective electrode cell assembly no matter what type of electrode cellassembly is laminated.

The bonded electrode/separator is heated in a heating part 50 and isclosely bonded in a rolling part 60. Thereafter, the separators 2 arecut and laminated to be manufactured in the form of an electrode cellassembly E in a separator cutting part 70. From the unwinder part to anelectrode cutting part may be referred to as a lamination part 100, andthereafter, the electrode cell assembly E is discharged toward asubsequent process by a discharge part 300 after being subjected to apredetermined inspection in an inspection part 200 (see FIG. 3 ).

The order of cutting, bonding, heating, and rolling in the laminationpart 100 may be changed according to the lamination type or order of thecell assembly to be manufactured. Since the above lamination process isa process performed in a typical lamination apparatus, a detaileddescription thereof will be omitted.

As shown in FIG. 3 , in the inspection operation after the laminationprocess, a short-circuit inspection for inspecting whether a currentflows when the current runs through the electrode cell assembly isperformed by a short-circuit inspection part 210. In addition, after theshort-circuit inspection, a vision inspection for inspecting anappearance defect, a dimension/width defect, and the like may beperformed by a vision inspection part 230 in which a charge coupleddevice (CCD) camera and the like are installed.

The main feature of the present invention is that the defectiveelectrode cell assembly including the connection tape is detected afterthe electrode cell assembly E is manufactured in the lamination process.

In the present invention, since the defective electrode cell assemblymay be detected by measuring the thickness of the electrode cellassembly, a thickness measuring part 220 may be disposed in theinspection part 200 after the electrode cell assembly E is manufactured.The defective electrode cell assembly is thicker than the normalelectrode cell assembly because the connection tape is included in theelectrode or separator. Thus, when the thickness measuring part 220 isinstalled in the inspection part 200, the defective electrode cellassembly is able to be detected. In one embodiment, the thicknessmeasuring part 220 may be disposed in front of the vision inspectionpart 230 configured to inspect the appearance, shape, dimensions, andthe like of the electrode cell assembly E, but the arrangement order ofthe thickness measuring part 220 is not limited thereto.

It is preferable that the thickness measurement of the electrode cellassembly E is able to be performed in a state of not coming into contactwith the electrode cell assembly E in order to operate a manufacturingline continuously without stopping the manufacturing line. For example,as a non-contact thickness measurement sensor, an ultrasonic sensor, adisplacement sensor, a laser sensor, a confocal thickness sensor, andthe like may be applied. However, in the present invention, rather thana displacement sensor or the like suitable for measuring a thickness ofa coating film, a confocal thickness sensor 80 configured to calculate adistance (thickness) by analyzing a wavelength of reflected light ispreferable in that the sensor is for measuring a total thickness of theelectrode cell assembly E. The confocal thickness sensor 80 may beinstalled to be movable in at least one of a vertical direction and ahorizontal direction in order to adjust a focus or a distance betweenthe confocal thickness sensor and the electrode cell assembly. In orderto move the confocal thickness sensor 80, the sensor may be installed onan XYZ stage. Since the XYZ stage is a well-known member used for linearmovement in the vertical direction and the horizontal direction (aleft-right direction and a front-rear direction), a description thereofwill be omitted.

When the defective electrode cell assembly is detected by the confocalthickness sensor 80, as shown in FIG. 3 , data (thickness data) relatedthereto is transmitted to a control part 400. For example, when ameasured thickness value is increased by more than a specific value incomparison with the normal cell assembly and maintained for a specificperiod of time, the control part 400 determines the electrode cellassembly to be a defective electrode cell assembly including aconnection tape. Meanwhile, the control part 400 may transmit a controlsignal to the confocal thickness sensor 80 in order to change a distancecontrol application mode of the confocal thickness sensor 80.

In addition, an encoder 410 installed at the third conveyor C3, forexample, the encoder 410 installed at a motor driving part of theconveyor transmits data on a location of the conveyor to the controlpart 400 in real time as the conveyor moves. The control part 400 isconnected to the encoder 410 and communicates therewith for power linecommunication (PLC) control, and thus even a point (location) b at whichthe defective electrode cell assembly is detected may be identified bythe encoder 410. In addition, since a discharge port c of the defectiveelectrode cell assembly in the discharge part 300 is determined, whenthe point b at which the defective electrode cell assembly is detectedis determined, the encoder 410 may also detect a distance C from thedefective electrode cell assembly to the discharge port. Accordingly,the control part 400 may receive the thickness data from the thicknessmeasuring part 220 (e.g., the confocal thickness sensor 80) to confirmthe defective electrode cell assembly, and receive the location b atthat time and data on the distance C to the discharge port c from theencoder 410 to calculate a time point at which the defective electrodecell assembly reaches the discharge port c. That is, when the distancedata is divided by a conveying speed of the conveyor, the time point atwhich the defective electrode cell assembly reaches the discharge part(the discharge port c) is obtained. This may be performed bypredetermined software built into the control part 400. In this case,since the defective electrode cell assembly is detected by the thicknessmeasuring part 220 installed in the inspection part 200, the distance Cbetween the detection point b and the discharge port c is very short,about 2 to 3 m, and there is no need to preserve measurement data for along period of time. In addition, since the distance may be detected bya single encoder installed at the conveyor (the third conveyor C3 inFIG. 2 ), the above calculation process is not complicated. Thus,according to the present invention, a time point at which the defectiveelectrode cell assembly is discharged may be very accurately obtainedwithout a large measurement error. That is, as shown in FIGS. 1 and 3 ,the discharge time point calculation process of the present invention ismuch simpler and has the advantage of high measurement accuracy ascompared with the related art of calculating the time point at which thedefective electrode cell assembly is discharged by including all of aconveying distance on a plurality of conveyors from a color sensorinstallation part a of an unwinder to a bonding part or a conveyingdistance A for a separator and a conveying distance B on anotherconveyor from a heating part to a discharge port c.

The control part 400 identifies the defective electrode cell assemblyfrom the data on the thickness of the electrode cell assembly measuredby the thickness measuring part 220, calculates a time point at whichthe defective electrode cell assembly reaches the discharge port c ofthe discharge part 300, and controls the discharge member 90 to separateand discharge the defective electrode cell assembly at the time point atwhich the defective electrode cell assembly reaches the discharge portc. That is, the discharge member 90, which receives a predeterminedcontrol signal for discharging the defective electrode cell assemblyfrom the control part 400, may adsorb the defective electrode cellassembly and remove the defective electrode cell assembly from aconveyor line for the normal electrode cell assembly. To this end, thedischarge member 90 includes an adsorbing member 92 capable of adsorbingthe electrode cell assembly and a moving member 91 capable of moving theadsorbing member 92 from the conveyor line. Alternatively, the conveyormay be configured such that a conveyor line for the defective electrodecell assembly is branched at a point of the discharge port c of theconveyor line for the normal electrode cell assembly. In this case, apusher (not shown) configured to push the defective electrode cellassembly to the branched conveyor line may be used as the dischargemember 90 that discharges the defective electrode cell assemblyaccording to the control signal of the control part 400.

According to the lamination apparatus 2000 of the present invention,since only the defective electrode cell assembly may be accuratelyseparated and discharged, there is no need to also discharge sparenormal electrode cell assemblies as in the related art.

Second Embodiment

FIG. 4 is a schematic diagram illustrating another embodiment of thelamination apparatus of the present invention.

The second embodiment has a form in which, as the thickness measuringpart 220, two confocal thickness sensors are disposed above and below anelectrode cell assembly.

For example, it is possible to measure a thickness of the electrode cellassembly in a non-contact manner even when one confocal thickness sensoris installed above or below the electrode cell assembly. However, asdescribed above, in the lamination apparatus, processes of applying apredetermined impact to electrodes and separators such as cutting of theelectrodes, cutting of the separators, heating, rolling, and the likeare performed, and thus the electrodes or the separators on the conveyorand the conveyor subjected to such an impact are subjected tovibrations. Such an impact or vibration is also transmitted in theelectrode cell assembly stage after laminating electrode/separator. Theconfocal thickness sensor measures the thickness of the electrode cellassembly by measuring a distance from the sensor to the electrode cellassembly, and thus, when the electrode cell assembly is subjected tovibrations, such as slightly bouncing on the conveyor due to vibrations,in some cases, the thickness of the electrode cell assembly may not beaccurately measured.

In the second embodiment, two confocal thickness sensors 81 and 82 arerespectively disposed above and below the cell assembly so that thethickness of the electrode cell assembly may be accurately measured evenin the above case. In the present embodiment, as shown in FIG. 4 , athickness of an electrode cell assembly E is measured by a differencebetween a distance x between the electrode cell assembly E and theconfocal thickness sensor 81 disposed thereabove and a distance ybetween the electrode cell assembly E and the confocal thickness sensor82 disposed therebelow. Thus, even when the electrode cell assembly Ereceives an impact caused by the vibration of the conveyor, since anabsolute value of a distance difference x-y (i.e., the thickness of theelectrode cell assembly E) is always constant, the thickness of theelectrode cell assembly E may be accurately measured.

Meanwhile, the upper and lower confocal thickness sensors 81 and 82 arefirmly fixed by one bracket 83. The bracket 83 is designed in a “C”shape to minimize the vibration of the confocal thickness sensor, andthe confocal thickness sensors 81 and 82 are mounted vertically on bothfront end parts 83 a and 83 b of the bracket 83, respectively. Thebracket 83 is installed on an XYZ stage and is movable in a vertical orhorizontal direction. Reference numeral 84 denotes a connection member84 for installing the bracket 83 on the XYZ stage.

According to the present embodiment, since the thickness of theelectrode cell assembly may be accurately measured even when an impactor vibration is inevitably generated in the lamination apparatus 2000, adefective electrode cell assembly including a connection tape may beextracted and only the defective electrode cell assembly may bedischarged from the discharge part 300.

Meanwhile, when FIG. 3 is related to an embodiment in which the controlpart 400 directly controls the confocal thickness sensor, dedicatedcontrollers 85 and 86 configured to control the confocal thicknesssensor 80 may be provided in FIG. 4 . The controllers 85 and 86 mayserve to control a focus or the like of each of the upper and lowerconfocal thickness sensors 81 and 82 and simultaneously serve totransmit thickness data measured from the confocal thickness sensor tothe control part 400. The control part 400 identifies the defectiveelectrode cell assembly from the thickness measurement data transmittedfrom the controllers 85 and 86, and at the same time, receives adistance between the point b at which the defective electrode cellassembly is detected and (the discharge port c of) the discharge partfrom the encoder 410 to calculate a time point at which the defectiveelectrode cell assembly reaches the discharge port. The control part 400sends data on the arrival time point of the defective electrode cellassembly and an operation signal to the discharge member 90 installed inthe discharge port c to control the discharge member 90 to remove thedefective electrode cell assembly from the conveyor.

FIG. 5 is a side view illustrating an actual example of the laminationapparatus 2000 to which the present invention is applied.

As illustrated in the drawing, as compared with to the case in which thecolor sensor is installed in the related art, according to the presentinvention, it can be seen that the defective electrode cell assembly maybe removed from the discharge port c with little or no measurement errorbecause a distance between the point b at which the defective electrodecell assembly is recognized and the discharge port c of the dischargepart is very short.

EXAMPLES Comparative Example

As in the related art, a color sensor was installed between an unwinderpart and an electrode cutting part of a lamination apparatus, and cellassemblies (a specific cell assembly and electrode cell assembliesbefore and after the specific cell assembly), which were presumed to bedefective electrode cell assemblies, were removed from a discharge portto ensure the discharge of the defective electrode cell assembly.

-   -   Total number of electrode cell assemblies manufactured: 29,546    -   Number of discharged cell assemblies considered as defective        electrode cell assemblies: 110 (0.372%)    -   Number of actual defective electrode cell assemblies: 35

As described above, a total of 110 cell assemblies were discharged as aresult of discharging the defective electrode cell assemblies by thelamination apparatus of Comparative Example. As a result of inspectingthe discharged cell assemblies again, the number of actual defectiveelectrode cell assemblies was 35.

EXAMPLE

When a confocal thickness sensor of the present invention was installedin an inspection part, the number of discharged defective electrode cellassemblies was 35 (0.118%).

Accordingly, according to the present invention, it can be seen thatmanufacturing yield can be improved by about 0.254%.

The method of discharging the defective electrode cell assembly by thelamination apparatus according to the present invention may besummarized again as follows.

First, after electrodes and separators are laminated to form anelectrode cell assembly E, a thickness of the electrode cell assembly ismeasured to detect a defective electrode cell assembly.

Further, a time point at which the defective electrode cell assemblyreaches a discharge part (more precisely, a discharge port c of thedischarge part at which the defective electrode cell assembly isseparated and discharged from a normal electrode cell assembly) iscalculated on the basis of distance data (e.g., distance data extractedfrom an encoder of a conveyor) between a point b at which the defectiveelectrode cell assembly is recognized (detected) and the discharge part.

Thereafter, the defective electrode cell assembly may be separated fromthe normal electrode cell assembly and discharged at the time point atwhich the defective electrode cell assembly reaches the discharge part.

Meanwhile, according to the present invention, only the defectiveelectrode cell assembly may be accurately detected, but a distancebetween a thickness measuring part and the discharge part may be furtherincreased as the apparatus becomes larger. Alternatively, a slight errormay occur in a process of calculating the arrival time point of thedefective electrode cell assembly due to an impact in a laminationprocess. In this case, in order to ensure the discharge of the defectiveelectrode cell assembly, one electrode cell assembly adjacent to thedefective electrode cell assembly may be discharged together with thedefective electrode cell assembly. However, even in the case of thedischarge of spare cell assemblies, there is no large measurement errorto the extent that up to four or five cell assemblies when there as manyas two or three cell assemblies before and after the cell assembly,which are estimated to be a defective electrode cell assembly, as in therelated art, are discharged. The reason is that, by measuring thethickness, the defective electrode cell assembly is detected after theelectrode cell assembly is manufactured, and accordingly, the defectiveelectrode cell assembly is accurately discharged due to the control ofthe distance/defect discharge time point.

In the above, the present invention has been described in more detailwith reference to the drawings and embodiments. However, since theconfiguration described in the drawings or embodiments described hereinis merely one embodiment of the present invention and do not representthe overall technical spirit of the invention, it should be understoodthat the invention covers various equivalents, modifications, andsubstitutions at the time of filing of this application.

DESCRIPTION OF REFERENCE NUMERALS

-   1 and 1′: electrodes-   2: separator-   10: electrode unwinder roll-   11: separator unwinder roll-   20: color sensor-   30: electrode cutting part-   40: bonding part-   50: heating part-   60: rolling part-   70: separator cutting part-   80: confocal thickness sensor-   90: discharge member-   91: moving member-   92: adsorbing member-   100: lamination part-   200: inspection part-   210: short-circuit inspection part-   220: thickness measuring part-   230: vision inspection part-   300: discharge part-   400: control part-   410: encoder-   C1: first conveyor-   C2: second conveyor-   C3: third conveyor-   E: electrode cell assembly-   a: color sensor installation part-   b: defective electrode cell assembly recognition point-   c: discharge port-   2000: lamination apparatus

1. A lamination apparatus for manufacturing an electrode cell assemblyby laminating an electrode and a separator respectively unwound from anelectrode roll and a separator roll, the lamination apparatuscomprising: a lamination part configured to laminate the electrode cellassembly; an inspection part configured to detect a defective electrodecell assembly by measuring a thickness of the electrode cell assembly; adischarge part configured to separate the defective electrode cellassembly from the lamination apparatus and to discharge the defectiveelectrode cell assembly from the lamination apparatus; and a controlpart configured to calculate a time point at which the defectiveelectrode cell assembly reaches the discharge part on the basis ofdistance data between a point at which the defective electrode cellassembly is detected and the discharge part and separate, the controlpart configured to discharge the defective electrode cell assembly whenthe defective electrode cell assembly reaches the discharge part.
 2. Thelamination apparatus of claim 1, further comprising a conveyorconfigured to receive the electrode assembly thereon, wherein the timepoint at which the defective electrode cell assembly reaches thedischarge part is obtained by dividing the distance data by a conveyingspeed of a conveyor.
 3. The lamination apparatus of claim 1, furthercomprising a conveyor driving part configured to convey the electrodecell assembly and an encoder installed at the conveyor driving part,wherein the distance data is detected by the encoder.
 4. The laminationapparatus of claim 1, wherein the inspection part includes a thicknessmeasuring part configured to measure a thickness of the electrode cellassembly and a vision inspection part configured to inspect at least oneof an appearance, a shape, and dimensions of the electrode cellassembly.
 5. The lamination apparatus of claim 4, wherein the thicknessmeasuring part is installed before the vision inspection part in aconveying direction of the lamination apparatus.
 6. The laminationapparatus of claim 1, wherein the lamination apparatus is configured tomeasure the thickness of the battery cell assembly in a non-contactmanner.
 7. The lamination apparatus of claim 6, further comprising aconfocal thickness sensor configured to measure the thickness of thebattery cell assembly.
 8. The lamination apparatus of claim 7, whereinthe confocal thickness sensor is installed on a stage configured to movein three dimensions.
 9. The lamination apparatus of claim 7, wherein theconfocal thickness sensor is an upper confocal thickness sensor, theapparatus further comprising a lower confocal thickness sensor, theupper and lower confocal thickness sensors being respectively disposedabove and below a conveyor configured to receive the electrode cellassembly thereon, and the apparatus is configured to measure thethickness of the electrode cell assembly by calculating a difference ofa distance between the electrode cell assembly and the upper confocalthickness sensor disposed thereabove and a distance between theelectrode cell assembly and the lower confocal thickness sensor disposedtherebelow.
 10. The lamination apparatus of claim 9, wherein the upperand lower confocal thickness sensors are mounted on a same bracket, andthe same bracket is installed on a stage configured to move in threedimensions.
 11. The lamination apparatus of claim 1, wherein the controlpart is configured to discharge one electrode cell assembly adjacent tothe defective electrode cell assembly together with the defectiveelectrode cell assembly.
 12. A method of discharging a defectiveelectrode cell assembly using a lamination apparatus, the methodcomprising: detecting the defective electrode cell assembly by measuringa thickness of the defective electrode cell assembly after the electrodeand the separator are laminated to form the defective electrode cellassembly; calculating a time point at which the defective electrode cellassembly reaches a discharge part of the lamination apparatus on thebasis of distance data between a point at which the defective electrodecell assembly is detected and the discharge part; and separating anddischarging the defective electrode cell assembly from a normalelectrode cell assembly at the time point at which the defectiveelectrode cell assembly reaches the discharge part.
 13. The method ofclaim 12, wherein the time point at which the defective electrode cellassembly reaches the discharge part is obtained by dividing the distancedata by a conveying speed of a conveyor of the lamination apparatus. 14.The method of claim 12, wherein the distance data is detected by anencoder installed at a conveyor driving part of the lamination apparatusconfigured to convey the defective electrode cell assembly.
 15. Themethod of claim 12, wherein the thickness of the defective electrodecell assembly is measured in a non-contact manner.
 16. The method ofclaim 15, wherein the thickness of the defective electrode cell assemblyis measured by a confocal thickness sensor.
 17. The method of claim 16,wherein the confocal thickness sensor is movable in at least one of avertical direction and a horizontal direction.
 18. The method of claim17, wherein the confocal thickness sensor is an upper confocal thicknesssensor, the lamination apparatus has a lower confocal thickness sensor,and the upper and lower confocal thickness sensors are respectivelydisposed above and below the electrode cell assembly, and the thicknessof the electrode cell assembly is measured by a difference of a distancebetween the defective electrode cell assembly and the upper confocalthickness sensor disposed thereabove and a distance between thedefective electrode cell assembly and the lower confocal thicknesssensor disposed therebelow.
 19. The method of claim 12, wherein thenormal electrode cell assembly adjacent to the defective electrode cellassembly is discharged together with the defective electrode cellassembly.